Can I drink distilled water is really two questions: is it drinkable, and is it a sensible way to treat a household supply. It is water with essentially everything dissolved removed, so it is drinkable and it tastes flat, because taste in water comes largely from the minerals a distiller strips out. Whether it is the right treatment is a separate matter.
What distillation actually does
A distiller boils water, captures the steam and condenses it back to liquid in a separate vessel. Anything that does not evaporate at that temperature stays behind in the boiling chamber: dissolved minerals, metals, salts, and the residue you scrape out afterwards. The USGS defines hardness as dissolved calcium and magnesium, classified from soft at 0 to 60 mg/L as calcium carbonate up to very hard above 180 mg/L, and distillation removes both completely. Microorganisms are killed by the boil and left behind. What does carry over is anything that boils at or below the temperature of water, which is why better distillers add a carbon post-filter for volatile organics.
Why it tastes flat
The character people recognize as the taste of water comes from dissolved minerals, and distillation removes all of them. The result reads as flat or empty to most palates, which is exactly the same reaction people have to reverse osmosis water for the same reason. This is a preference issue rather than a defect, and it is why remineralizing cartridges are sold for both technologies. Distilled water also picks up a slight taste from whatever container it sits in, since with nothing dissolved in it, it is an aggressive solvent for the trace material in plastics.
When a home distiller is the right buy
Distillation is thorough and it is slow. A countertop distiller produces a batch over several hours, uses meaningful electricity to boil every drop, and needs the scale residue cleaned out of the chamber regularly. That makes it a good fit where you need a small volume of very pure water and want a device that is independent of water pressure, plumbing and cartridge supply chains: a rental with no plumbing access, a CPAP machine, a steam iron, or a household on a supply with a broad mix of dissolved contaminants. For general drinking water on a normal supply, an under-sink filter is cheaper to run.
What distillation does not fix
It treats one batch at a time, so it does nothing for the water reaching your shower, your washing machine or your water heater. If your complaint is scale on the fixtures or spotting on glass, distilling drinking water changes nothing about any of that; that is a softener's job. It also does not protect the plumbing, since the untreated supply still runs through every pipe in the building. Treat a home distiller as a drinking water appliance rather than as water treatment, and if you have a whole-house complaint, see our softener installation guide instead.
Questions people ask about can i drink distilled water
Why does distilled water taste flat?
Because the dissolved calcium, magnesium and other minerals that give water its familiar taste are left behind in the boiling chamber. Nothing is wrong with it; there is simply nothing dissolved in it.
Does distillation remove bacteria?
Yes. The boil kills microorganisms and they do not carry over with the steam, so distillation handles biological contamination as well as dissolved minerals and metals.
Can I use distilled water in appliances?
It is the standard choice for steam irons, humidifiers and CPAP machines precisely because it leaves no mineral scale in the heating element or reservoir.
Is a distiller a substitute for a water softener?
No. A distiller treats a batch of drinking water. A softener treats everything entering the house, which is what stops scale in the heater, the shower and the laundry.